1. Field of the Invention
The present invention relates to an impedance roller for use in a video cassette tape recorder (hereinafter "VCR") and more particularly, to an impedance roller for enabling to absorb and reduce the vibration of a tape by providing an inertia spring damper member defining a plurality of inertia masses and elastic members such as elastic rubber to the impedance roller on which the tape contacts and travels.
2. Description of the Prior Art
Various impedance rollers for use in the VCR deck mechanism serve as a tape guide which is structured with basic components so as to rotate by the frictional force of the tape. Therefore, such impedance rollers function for reducing the longitudinal vibration component of the tape by the inertia force according to the inertia moment of the impedance rollers.
As shown in FIG. 1, a conventional impedance roller 10 includes a shaft hole 10a disposed at the center portion thereof and a shaft fixed to a main chassis of the VCR deck at the one end and the other end, inserted to the shaft hole 10a for rotatably coupling.
FIG. 2 is a schematic diagram illustrating the operation of the conventional impedance roller 10 shown in FIG. 1 as the spring mass vibration system, wherein K.sub.1 and K.sub.2 are a spring constant according to the length up to a predetermined distance point of the tape wound around the impedance roller 10, M is an equivalent mass of the impedance roller, and F is a force transferred to the impedance roller 10 from the tape.
In the above-mentioned spring mass vibration system, since the impedance roller 10 is rendered to vibrate by the force F transferred by the longitudinal vibration and frictional force of the tape, the longitudinal vibration component of the tape becomes to reduce a certain degree by the inertia of the impedance roller 10.
However, although thus such impedance roller 10 having the above-described structure exhibits a certain reduction of the longitudinal vibration component, such impedance roller 10, in CUE/REV mode and ultra-high speed search playback mode thereof, is provided a travelling speed of the tape which is reached 3-12 times speed in a standard record and a playback mode and 9-36 times speed in a long time record and a playback mode relative to normal playback mode. Therefore, such impedance roller 10 has a problem that the longitudinal component vibration of the tape cannot be effectively reduced.